MINNEAPOLIS (WCCO) — As investigators continue to look into the Boston Marathon bombings, questions are growing about whether there was an American intelligence failure.

Tamarlan Tsarnaev was questioned by the FBI shortly before he went on a six-month trip to his native Chechnya in 2011.

The FBI interview came at the request of the Russian government.

The FBI interviewed Tamarlan Tsarnaev because the Russian government had evidence that Tsarnaev
was “a follower of radical Islam” and that he was planning to visit Chechnya and nearby Dagestan to join “unspecified underground groups.”

Those are predominantly Muslim regions which are home to a number of radical groups, some with ties to Al Qaeda. But the FBI determined Tsarnaev was not a threat.

He went to Chechnya for six months and when he came back, the FBI never followed up. Some members of Congress are demanding an investigation.

Sen. Al Franken appeared on WCCO Sunday Morning.

“This is something that is very serious and something we have to look into and there’s no question about that,” Sen. Franken said. “I don’t know we can say we are going to get 100 percent of every one of these things. This is unacceptable for any of this to happen.”

Sen. John McCain is joining two other senators who are even asking that the surviving suspect, Dzhokar Tsarnaev, be tried as an enemy combatant for an act of war. That would allow prosecutors to try him in a military tribunal where he would not be afforded constitutional rights.

But constitutional experts say that is unlikely because the younger Tsarnaev is an American citizen and the acts he is accused of took place on American soil.

The New York Times is reporting that the FBI interview held up the older Tsarnaev’s citizenship application.